I am writing a document for which I need the margin to be exactly as follows: left, right, top and bottom text margin all equal to 1in, distance from bottom of the paper to page number equal to 0.75in (I don't have any footnote or header to set).

I tried to use the fullpage package in LaTeX but it does not give me the 0.75in to the page number. Is there a way to force that? I tried to set manually the margins for a 8.5x11 paper but I am not succeeding.

Also it seems to me that depending on which machine I use to compile my tex file, I get different margins, even when I set them up manually (without using geometry). Is it possible?

Using the geometry package things seem to work a bit better now (I changed machine and the problem with the paper width previously mentioned disappeared).

\usepackage[margin=1in,footskip=0.25in]{geometry}

gives me without problem upper, right and left margin of 1in. But the lower margin is 1.2in and I can't change it to be 1in even by using bottom=1in or bottom=0.8in. I really don't see how this can happen. Maybe a problem with the spacing between lines? The class files I am using can be fund at http://www.math.ucla.edu/help/tex/uclathes/

I erased the margin settings of uclath12.clo as the margin I need are different from the ones that this file gives. Thank you.

@David I realize this is a fairly old post but I'm facing the exact same problem. Would you mind sharing the uclath12.clo that you changed (or the way you changed it) so I don't have to figure it out all myself? Much appreciated!
– janMar 29 '16 at 8:02